16-28932356-C-T

Position:

• chr16-28932356-C-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_001770.6(CD19):​c.99C>T​(p.Asn33=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000076 in 1,579,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000077 (0 hom.)
• Consequence: CD19 NM_001770.6 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.751

Genes affected

CD19 (HGNC:1633): (CD19 molecule) This gene encodes a member of the immunoglobulin gene superfamily. Expression of this cell surface protein is restricted to B cell lymphocytes. This protein is a reliable marker for pre-B cells but its expression diminishes during terminal B cell differentiation in antibody secreting plasma cells. The protein has two N-terminal extracellular Ig-like domains separated by a non-Ig-like domain, a hydrophobic transmembrane domain, and a large C-terminal cytoplasmic domain. This protein forms a complex with several membrane proteins including complement receptor type 2 (CD21) and tetraspanin (CD81) and this complex reduces the threshold for antigen-initiated B cell activation. Activation of this B-cell antigen receptor complex activates the phosphatidylinositol 3-kinase signalling pathway and the subsequent release of intracellular stores of calcium ions. This protein is a target of chimeric antigen receptor (CAR) T-cells used in the treatment of lymphoblastic leukemia. Mutations in this gene are associated with the disease common variable immunodeficiency 3 (CVID3) which results in a failure of B-cell differentiation and impaired secretion of immunoglobulins. CVID3 is characterized by hypogammaglobulinemia, an inability to mount an antibody response to antigen, and recurrent bacterial infections. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2020]

RABEP2 (HGNC:24817): (rabaptin, RAB GTPase binding effector protein 2) Predicted to enable GTPase activator activity and growth factor activity. Involved in regulation of cilium assembly. Located in cytosol; intracellular membrane-bounded organelle; and microtubule organizing center. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP6: Variant 16-28932356-C-T is Benign according to our data. Variant chr16-28932356-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 1624512.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.751 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CD19	NM_001770.6	c.99C>T	p.Asn33=	synonymous_variant	2/15	ENST00000538922.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CD19	ENST00000538922.8	c.99C>T	p.Asn33=	synonymous_variant	2/15	5	NM_001770.6	P3
CD19	ENST00000324662.8	c.99C>T	p.Asn33=	synonymous_variant	2/15	1		A2
RABEP2	ENST00000566762.1	c.-150+3908G>A		intron_variant		4
CD19	ENST00000565089.5	n.135C>T		non_coding_transcript_exon_variant	2/13	2

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151700 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000402 AC: 1 AN: 248970 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135118

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000770 AC: 11 AN: 1428162 Hom.: 0 Cov.: 38 AF XY: 0.00000844 AC XY: 6 AN XY: 710632

Gnomad4 AFR exome AF: 0.0000306

Gnomad4 AMR exome AF: 0.0000228

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000233

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000641

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151700 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74124

Gnomad4 AFR AF: 0.0000242

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 27, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	4.1
DANN	Benign	0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs767961417; hg19: chr16-28943677;